MISAO Project

Japanese version       Home Page       Updated on July 18, 2001

July 16, 2001

    MisV cross identifications    

MISAO Project Announce Mail (July 16, 2001)

Hello. I am Seiichi Yoshida working on the MISAO project.

The number of new variable stars discovered in the course of the MISAO Project reached to 1119 on May 30. But most of them have observations at only a several nights, so their type is uncertain.

There may be some valuable objects among them, like novae or some cataclysmic variables. In order to confirm that, we have to look up past images like the DSS (Digitized Sky Survey). But it takes some time to do it for all new variable stars.

We have been referring to two star catalogs, the GSC 1.1 and the USNO-A2.0, and an infrared catalog, the IRAS Point Source Catalogue, and picking up counterpart data of every MisV star. If there is data in those catalogs, we can say the star is not a nova or cataclysmic variable.

However, many MisV stars are not recorded in any of those catalogs, probably because the MISAO Project new variable stars are very faint in common. So we could not select small number of remarkable candidates of novae or cataclysmic variables among many new variable stars.

Recently, many new star catalogs and infrared catalogs are released. Then John Greaves, the United Kingdom, and Seiichi Yoshida researched those new catalogs to find the counterpart of every MisV star.

We worked on the following catalogs.

  • 2MASS (The Two Micron All Sky Survey)

    The infrared catalog all over the sky. Although data of only half of the whole sky is released now, all data will be released in 2002. It contains about 300 million data and covers very faint stars. The position is as accurate as, or more accurate than, the general star catalogs. We can also judge whether a star is a red variable or not based on the J-band and K-band magnitude. The data can be retrieved at the following site.


  • UCAC1 (USNO CCD Astrograph Catalog)

    The accurate astrometric catalog covering down to 16 mag. The UCAC2 will be released in 2002, and the data all over the whole sky will be released in 2003. The data can be retrieved at the following site.

    VizieR Service

  • GSC 2.2 (Guide Star Catalog II)

    The next version of the well-known star catalog, GSC 1.1. Although the GSC 1.1 covers down to 13-16 mag, the GSC 2.2 contains stars down to 19 mag. The magnitude in two bands are recorded. The GSC 2.2 contains about 435 million data. The final version, GSC 2.3, will be released in 2002. The data can be retrieved at the GSC 2.2 home page.
  • MSX5C (Midcourse Space Experiment Point Source Catalog)

    The infrared catalog along the galaxy plane. It contains very faint stars. It is useful especially where the 2MASS data is not yet released. The data can be retrieved at the following site.

    VizieR Service

The recent new catalogs contain many faint stars. Especially, most of the red variable stars, Mira-type or semi-regular type, which appears very bright on CCD images, are recorded in the 2MASS catalog.

After this research, only 27 objects among 1119 are selected, which has no counterpart data in any catalogs.

John Greaves and Seiichi Yoshida checked the past images for the rest 27 stars using the following web services, and revealed they are not novae or cataclysmic variables.

USNO Flagstaff Station Integrated Image and Catalogue Archive Service

Astronomical Image On-line Access Interface

The identification results of this research are merged in the MisV catalog available at the MISAO Project home page.

In the IBVS 5135 issued on July 9:

The 76th Name-List of Variable Stars

the permanent designations are assigned to 179 MisV new variable stars. For example, MisV0001 should be called V4652 Sgr, MisV0002 should be called V523 Aur after this. These GCVS designations are also merged in the MisV catalog available at the MISAO Project home page.

The past MISAO project announce mails are available at:


Seiichi Yoshida

Copyright(C) MISAO Project (comet@aerith.net). All rights reserved.